The present invention relates to rectangular parallelopipedal blocks capable of interfitting without considering the direction of each block to be connected. A large number of rectangular parallelopipedal blocks having the same shape and the same size and having concavities and convexities formed on the surfaces thereof are aligned and connected by interfitting adjacent surfaces.
Construction of structures by aligning and connecting a large number of rectangular parallelopipedal blocks has been utilized for the production of walls, block walls, and so forth. Particularly when radioactive shield walls are produced by using lead, graphite, concrete, etc., in the field of nuclear power, a block structure has been utilized. Also, in the field of toys, block toys are used for making and assembling products of various shapes by connecting a large number of small blocks.
When a large number of blocks are to be aligned and connected, concavo-convexities are formed on the surfaces of each block so that adjacent surfaces can be fitted to one another and adhesion between the blocks can be improved by eliminating the gap between the adjacent blocks.
However, in order to insure smooth fitting of the concavo-convexities on the surfaces of adjacent blocks, it is necessary to fit them by confirming, one by one, the longitudinal direction, the transverse direction and the vertical direction of each block. The work of confirming the directions or orientation of each block is troublesome.